Modern inventory systems, such as those in mail-order warehouses, airport luggage systems, and custom-order manufacturing facilities, face significant challenges in responding to orders or requests for inventory items. In inventory systems tasked with responding to large numbers of diverse inventory requests, slow responses to inventory requests may result in an ever-increasing backlog of requests. Delays produced by such backlogs can result in lost business, wasted manpower, and other forms of economic loss.
Automation may reduce the amount of time it takes to identify and select requested items and to package orders. Nonetheless, the shipment of completed orders may depend on occasional or periodic events with no scheduling flexibility. For example, the shipment of a particular group of orders may be delayed until a delivery truck responsible for delivering that group of orders arrives at the facility. Once the delivery truck arrives, shipment may be further delayed as orders designated for a particular destination or carrier are identified and collected for shipping. As a result, the backlog in packed orders may overrun the packing area, prevent work on other orders from proceeding and, in general, reduce the throughput of the facility.